The present invention relates to computer disk drives and, more particularly, to a disk clamp for a disk drive.
Disk drive data storage systems typically include one or more data storage disks and a spindle motor for rotating the disks. The spindle motor lies within a rotatable spindle hub that supports the disks, and a clamp secures the disks to the hub.
Data storage disks have a central bore that receives the spindle motor hub. A typical disk clamp includes a disk-shaped body and a number of screws that secure the body and the disks to the hub. Tightening of the screws forces the clamp body against the uppermost disk, of a disk stack, and the clamp body against the hub, coupling the disks and intervening spaces to the hub so that the disks and the hub rotate together.
Some prior art disk clamps include a disk contact surface that is rounded. During operation of the disk drive, the rounded contact points compress or xe2x80x9cdigxe2x80x9d into an adjacent disk or spacer. This compressive force is transmitted radially outward on the disk and the radial force can distort or deform the disk from a normally planar shape into a cone-like or warped shape. This deformation makes it much more difficult to read data from the disk or write data on it. Specific examples of some prior art clamps include the U.S. Pat. Nos. 5,838,516; 5,875,171; 5,777,832; 5,880,906; 5,274,517; 5,490,024; 5,528,434; and 5,790,346. Although each of these prior art clamps may have specific constructions and improvements, one common structural characteristic is that each incorporates a curved or rounded surface which comes into contact with a disk or spacer mounted over the hub of a disk drive.
Other references disclosing disk clamps or related components include the U.S. Pat. Nos. 5,790,345; 5,517,376; and 5,333,080.
The clamp of the present invention avoids many of the disadvantages of the prior art clamps. The clamp of this invention provides a flat contact surface, reducing the radially directed force which results in disk deformation. The invention also provides undercuts adjacent the disk contact surface, further reducing the deformation causing loads. The clamp of the present invention provides a simple construction that minimizes the cost of fabrication and assembly and yet still provides effective and reliable operation.
In accordance with a preferred embodiment of the present invention, a disk clamp is provided that secures one or more data storage disks to a hub. The clamp includes a generally flat body having top and bottom faces and a center bore through which a portion of the hub extends. The body also defines on its bottom face a protuberance and a pair of grooves positioned on opposite radial sides of the protuberance. This protuberance has a flat distal surface for engaging a data storage disk. The body includes one or more securing bores for receiving securing members such as screws, and also includes access bores which provide access to bores formed on the hub which receive weights that balance the clamp, disks and spacers during rotation. The securing and access bores extend through the body and are geometrically arranged around the center bore. The body also has one or more arcuate grooves formed on its top face, proximate the securing bore or bores for distributing the securing force generated by the securing members extending through the corresponding securing bores. The portion of the body defined between opposing grooves on the top and bottom faces can also be collectively referred to as a web portion of the clamp.